1. Rheumatology Unit, University of Verona, Pz Scuro 10, 37135, Verona, Italy
2. Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA
3. INSERM UMR 1033, Université de Lyon, Hôpital E Herriot, Lyon, France
4. Rheumatology Department, Hospital Clinic, CIBERehd, IDIBAPS, University of Barcelona, Barcelona, Spain
5. Division of Rheumatology, Medicine Department, Southern Hospital Trust, Trondheim, Norway
6. Amsterdam UMC, location VUmc, Amsterdam, the Netherlands
7. University of Novi Sad, Faculty of Medicine, Novi Sad, Serbia
8. Clinical Center of Vojvodina, Clinic for Orthopedic Surgery, Novi Sad, Serbia
9. Metabolic Bone Centre, Northern General Hospital Sheffield, UK
10. Department of Gastroenterology, Infectious Diseases, and Rheumatology, Charité - Universitätsmedizin Berlin, Berlin, Germany
11. Epidemiology Unit, German Rheumatism Research Centre, Berlin, Germany
12. CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands
13. Biomedical Research Center, Hasselt University, Agoralaan, Gebouw D, Diepenbeek, Belgium